kristianmandrup / objectschemajs

Advanced schema enforced JavaScript objects.

  

objectschema.js

Advanced schema enforced JavaScript objects.

This is a light weight open source package for use on server or in browser. The source code is available on GitHub where you can also find our issue tracker.

Features

• Type casting
• Custom data types
• Field default value
• Field value transformation with getter and setter
• Strict and relaxed schemas
• Document nesting with support for self referencing
• Change tracking, data commits and rollbacks
• Advanced field validation

Related Projects

• Contextable.js: Simple, unopinionated and minimalist framework for creating context objects with support for unopinionated ORM, object schemas, type casting, validation and error handling and more.
• Validatable.js: A library for synchronous and asynchronous validation.
• Handleable.js: A library for synchronous and asynchronous error handling.
• Typeable.js: A library for checking and casting types.

Install

Run the command below to install the package.

$ npm install --save objectschema

Example

import {
  Document,
  Schema
} from 'objectschema';

let bookSchema = new Schema({
  fields: {
    title: {
      type: 'String'
    }
  }
});

let userSchema = new Schema({
  fields: {
    name: { // field name
      type: 'String', // field type
      validate: [
        {
          validator: 'presence',  // validator name
          message: 'is required' // validator error message
        }
      ]
    },
    books: {
      type: [bookSchema],
      validate: [
        {
          validator: 'presence',
          message: 'is required'
        }
      ]
    }
  }
});

let data = {
  name: 'John Smith',
  books: [
    {
      title: 'True Detective'
    }
  ]
};

let user = new Document(userSchema, data);
await user.validate({quiet: true});
user.isValid(); // -> false

API

This package consists of two core classes. The Schema class represents a configuration object and the Document represents a data object defined by the Schema. There is also the Field class which represents a document field.

This package also integrates typeable.js module for type casting and validatable.js for validating fields.

Schema

Schema represents a configuration object which configures the Document. It holds information about fields, type casting, how fields are validated and what the default values are.

A Schema can also be used as a custom type object. This way you can create a nested data structure by setting a schema instance for a field type. When a document is created, each schema in a tree of fields will become an instance of a Document - a tree of documents.

Schema({fields, strict, validatorOptions, typeOptions})

A class for defining document structure.

Option	Type	Required	Default	Description
fields	Object,Function	Yes	-	An object with fields definition. You should pass a function which returns the definition object in case of self referencing.
strict	Boolean	No	true	A schema type (set to false to allow dynamic fields not defined in schema).
validatorOptions	Object	No	validatable.js defaults	Configuration options for the Validator class, provided by the validatable.js, which is used for field validation.
typeOptions	Object	No	typeable.js defaults	Configuration options for the cast method provided by the typeable.js, which is used for data type casting.

new Schema({
  fields: { // schema fields definition
    email: { // a field name holding a field definition
      type: 'String', // a field data type provided by typeable.js
      defaultValue: 'John Smith', // a default field value
      validate: [ // field validations provided by validatable.js
        { // validator recipe
          validator: 'presence', // validator name
          message: 'is required' // validator error message
        }
      ]
    },
  },
  strict: true, // schema mode
  validatorOptions: {}, // validatable.js configuration options (see the package's page for details)
  typeOptions: {} // typeable.js configuration options (see the package's page for details)
});

This package uses typeable.js for data type casting. Many common data types and array types are supported, but we can also define custom types or override existing types through a typeOptions key. Please check package's website for a list of supported types and further information.

By default, all fields in a schema are set to null. We can set a default value for a field by setting the defaultValue option.

Validation is handled by the validatable.js package. We can configure the package by passing the validatorOptions option to our schema which will be passed directly to the Validator class. The package provides many built-in validators, allows adding custom validators and overriding existing ones. When a document is created all validator methods share document's context thus we can write context-aware checks. Please see package's website for details.

Document

A document is a schema enforced data object. All document properties and configuration options are defined by the schema.

Document(schema, data, parent)

A class for creating schema enforced objects.

Option	Type	Required	Default	Description
schema	Schema	Yes	-	An instance of the Schema class.
data	Object	No	-	Initial data object.
parent	Document	No	-	Parent document instance (for nesting documents).

Document.prototype.$parent: Document

Parent document instance.

Document.prototype.$root: Document

The first document instance in a tree of documents.

Document.prototype.$schema: Schema

Schema instance.

Document.prototype.$validator: Validator

Validator instance, used for validating fields.

Document.prototype.applyErrors(errors): Document

Deeply populates fields with the provided errors.

doc.applyErrors([
  {
    path: ['name'], // field path
    errors: [
      {
        name: 'ValidatorError', // error class name (ValidatorError or Error)
        validator: 'presence',  // validator name
        message: 'is required' // validator message
      }
    ]
  },
  {
    path: ['newBook', 'title'],
    errors: [
      {
        name: 'ValidatorError',
        validator: 'absence',
        message: 'must be blank'
      }
    ]
  },
  {
    path: ['newBooks', 1, 'title'],
    errors: [
      {
        name: 'ValidatorError',
        validator: 'presence',
        message: 'is required'
      }
    ]
  }
]);

Document.prototype.clear(): Document

Sets all document fields to null.

Document.prototype.clone(): Document

Returns a new Document instance which is the exact copy of the original.

Document.prototype.collectErrors(): Array

Returns a list of errors for all the fields (e.g. [{path: ['name'], errors: [ValidatorError(), ...]}]).

Document.prototype.commit(): Document

Sets initial value of each document field to the current value of a field. This is how field change tracking is restarted.

Document.prototype.equals(value): Boolean

Returns true when the provided value represents an object with the same fields as the document itself.

Document.prototype.getPath(...keys): Field

Returns a class instance of the field at path.

Option	Type	Required	Default	Description
keys	Array	Yes	-	Path to a field (e.g. ['book', 0, 'title']).

Document.prototype.hasErrors(): Boolean

Returns true when no errors exist (inverse of isValid()). Make sure that you call the validate() method first.

Document.prototype.hasPath(...keys): Boolean

Returns true when a field path exists.

Option	Type	Required	Default	Description
keys	Array	Yes	-	Path to a field (e.g. ['book', 0, 'title']).

Document.prototype.isChanged(): Boolean

Returns true if at least one document field has been changed.

Document.prototype.isValid(): Boolean

Returns true when all document fields are valid (inverse of hasErrors()). Make sure that you call the validate() method first.

Document.prototype.invalidate(): Document

Clears errors on all fields (the reverse of validate()).

Document.prototype.populate(data): Document

Applies data to a document.

Option	Type	Required	Default	Description
data	Object	Yes	-	Data object.

Document.prototype.reset(): Document

Sets each document field to its default value.

Document.prototype.rollback(): Document

Sets each document field to its initial value (last committed value). This is how you can discharge document changes.

Document.prototype.toObject(): Object

Converts a document into serialized data object.

Document.prototype.validate({quiet}): Promise(Document)

Validates document fields and throws a ValidationError error if not all fields are valid unless the quiet is set to true.

Option	Type	Required	Default	Description
quiet	Boolean	No	false	When set to true, a ValidationError is thrown.

try {
  await doc.validate(); // throws a ValidationError when fields are invalid
}
catch (e) {
  // `e` is an instance of ValidationError, which holds errors for all invalid fields (including those deeply nested)
}

Field

When a document field is defined, another field with the same name but prefixed with the $ sign is set. This special read-only field holds a reference to the actual field instance.

let user = new Document(schema);
user.name = 'John'; // -> actual document field
user.$name; // -> reference to document field instance
user.$name.isChanged(); // -> calling field instance method

Field(owner, name)

A field class which represents each field on a document.

Option	Type	Required	Default	Description
owner	Document	Yes	-	An instance of a Document which owns the field.
name	String	Yes	-	Field name

Field.prototype.$owner: Document

A reference to a Document instance on which the field is defined.

Field.prototype.name: String

Field name.

Field.prototype.clear(): Field

Sets field and related sub fields to null.

Field.prototype.commit(): Field

Sets initial value to the current value. This is how field change tracking is restarted.

Field.prototype.defaultValue: Any

A getter which returns the default field value.

Field.prototype.equals(value): Boolean

Returns true when the provided value represents an object that looks the same.

Field.prototype.hasErrors(): Boolean

Returns true when no errors exist (inverse of isValid()). Make sure that you call the validate() method first.

Field.prototype.initialValue: Any

A getter which returns the initial field value (last committed value).

Field.prototype.isChanged(): Boolean

Returns true if the field or at least one sub field have been changed.

Field.prototype.isValid(): Boolean

Returns true if the field and all sub fields are valid (inverse of hasErrors()). Make sure that you call the validate() method first.

Field.prototype.invalidate(): Field

Clears the errors field on all fields (the reverse of validate()).

Field.prototype.reset(): Field

Sets the field to its default value.

Field.prototype.rollback(): Field

Sets the field to its initial value (last committed value). This is how you can discharge field's changes.

Field.prototype.validate(): Promise(Field)

Validates the value and populates the errors property with errors.

Field.prototype.value: Any

A getter and setter for the value of the field.

ValidationError

ValidationError(message, code)

A validation error class which is triggered by method validate when not all fields are valid.

Option	Type	Required	Default	Description
paths	String[][]	No	[]	A list of all invalid document paths (e.g. [['friends', 1, 'name'], ...])
message	String	No	Validation failed	General error message.
code	Number	No	422	Error code.

ValidatorError

ValidatorError(validator, message, code)

A validator error class, provided by the validatable.js, which holds information about the validators which do not approve a value that has just been validated.

Option	Type	Required	Default	Description
validator	String	Yes	-	Validator name.
message	String	No	null	Validation error message.
code	Integer	No	422	Error status code.

License (MIT)

Copyright (c) 2016 Kristijan Sedlak <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.